SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abdd52e35471bf8698dd2df2973ccebe8a8beadf5ca5fdd64bdb30c6fa11592e' 
  AND token = 'xXD6gaxBzVQNA6vK+RAewtWgqYUnM3P4BLJP3sN/of0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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