SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4b74b589144ffc37c1e69f3ef27009a8bd29d621f77e0a5677ddad378745a85' 
  AND token = 'WXc53mWUYOjkjrOqMcTXQSAuapWhjpcVF2uDf9YFPCo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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