SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f1f538b4bce5ccfc351da2756bc343dfe2f5a4a54a006adfe743171ddd522e0' 
  AND token = 'F+z9mpcB7UxKhj3S/kEwYnmdxR5LbI5cqxxNqwGl0CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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