SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '17e0a72e683bb1031ab0d62d27a54f5e224cbdd15c2339b6a58aea75988d0a45' 
  AND token = 'LXo+iSqJXo0BcTffPKJhr3XYEr/QJG9HD2BwnpBZHds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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