SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39502cea888b22adf57c52fda974c67af0ae06b2637d8baec3aa46965dd420bc' 
  AND token = 'LMYE9SJchIG2xGLzx+1BqQUwFbtdWdLI3wX5elm426o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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