SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af79646efad00e9db43fb925baee4894bce0a67b6c4f877234402945146e3321' 
  AND token = 'yv+9ihWnL/+zscGBYjVOM6d83uJ8QBbZkQJxIfSa74U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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