SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c888d33980db1e5da10e6f407f0bfcbbbe08590cc2a5f2dd705ac40c322aeeb5' 
  AND token = 'a8aOYHK+7eDzmt1GhvtaO9FTAjumLlp1eX0Yyh+rgyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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