SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8200248f56371e53dcc2a541abaae474b8fc199e17097a8ae9db87cbae9cef3d' 
  AND token = 'yLqF3wWYcgG76YiiMx/dtuX7G+jeon75sKYWK1QUB9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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