SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47f03f90b7d03e41a0118545741d777f3c04e9818c45efe600b7e4c30dc09d00' 
  AND token = 'VLKEuXoc+gcElwm5CMhtq8rJwdWGu5QXuRFJ904RqF8=' 
  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"
    }
  }
}