SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '640e8b1e49582b86773940bd32ab44782d55eae9f60489c5b61a407d96606cc0' 
  AND token = '+ICQeB7j9NcpI4ou9uNzLgm1XFnJTPR+kj+vq/Swhoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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