SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '057da13d39f1467141d66232e94c138489df4438799fe1cbc2001504dbd0877a' 
  AND token = 'pUOeAsHjyPj83oOfimf5UeOjAZ9kXwbSwjZpvA4OoWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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