SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '421f605571edd4b3eedfe7fbc0b95f0dded2b61123b68134170e33b45b90145e' 
  AND token = 'amaSr9PkQFAGv0o5zsT7flwE7O8wFr0UEKLFT5l+1C8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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