SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '435d72eb0f16875456c2c9b3ff0b68e043023afd98655a6e4b74bf3a95abfff2' 
  AND token = 'uzFFlfn/r7TjUjzE5XXTII7Jkq6hOjx1msYPt0EFWPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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