SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc8ef64049bf9c9d4fc9ada4001305ffbdb3bd2543d07862bad95713d25cc41a' 
  AND token = 'byalFccjNBcc+iOAyOfb/d6DBYuuhz0fBbtIZo+XVW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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