SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f059709a1fbd5369405b88ae137d6675d7720e6b45745730d5f8022ce858d6e' 
  AND token = '6tq8QviWpf+VzrxcBZAvoadTDIjL/2PqseivPZNfWAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}