SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53fcbac96411aadfd76b4a7065dba36852e0263785429c2dafbe0f2fb307910c' 
  AND token = 'jBDenr5P99l1Hmv76Q6QRFSKwo57irYFbfFjQAGcpnw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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