SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77a4f15853378bd4e1c29e7331de1c85a800b607763d712edd58f24fb05e49dc' 
  AND token = 'VTUwZOVQhi+NPuAA6Kd/ShXAHH+B2cTNf5mvPa1dJws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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