SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6ba3ccb1cd86760a312b0c858d41b045827f62c57e98bcadb0541eabe91d4a39' 
  AND token = '3NQQHpGY9fz7yVvtpswL5VBJY0VyD+P0Od9Rz6wsmD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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