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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57582c1a2b0bdea9fc15c2a5ed041b2dad7d11010c43670e7f2a903624da11f9' 
  AND token = 'R4nR+UfuN5ap7P+vJ0dJzsCCtQNOUJL72oE1Rz9Uu9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}