SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64adb542d6dd30b43443a0d30b17ed5b6c12b4ca1d4312b6cb0422de8aaec57b' 
  AND token = 'Si8FFoPk7M9nzMUOVVOEfclJ4ouvRXXDAZ7ag3NRQn0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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