SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee9607b243b061aaa03958a628a0aaa563f81c0f2d9702845d81e222f25f95f8' 
  AND token = 'sY/0VKyMzZKaOEytGP+xT/OdjmnVOOxVhbBhmoaCrns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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