SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f4111acde89c8f69bf7e2a062d925d86e45678a4a51d1aaf3c1f9016a398559' 
  AND token = '4rLQYFFto9hDyjvCsHPhiBJGRXvDOkeuZtgw9Rf4C6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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