SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6b1053fccc237223fcb22f94beba1fbd6b6c0708b08e75e13dfdec1ae4d9ca53' 
  AND token = '8u4uH6fuTMrK9sloY1LQm0rpRJVF/fe52MYziyeq/kA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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