SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71072992a5a5cfbba9f6d789452fc1d78665c3c1166924eb840219994b8f0d38' 
  AND token = '+a8ULBHUJFVTtsllxnp2kemXulbC0HQdW8FV//hXhAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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