SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12d65f08101cbbc3b3b4ff61ac7f47d5974bf85abeb21436114b060f7785433d' 
  AND token = '4YtmHUPs1tduXAl7Qy3sqnIStylkzBuCdBg50MtgyIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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