SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '888712b894dee2e19b25973a81f6f0d05328567714d9efcd5331bf8d10edc774' 
  AND token = 'rmm4xj/dYHuJMkgvnUJmS0bTzSOJfJmYPK8tGEW8TfE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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