SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '171926ab8598757b6329d1c8097c5ab53c94a1cb6a4fcc44a410ebfd504d8b53' 
  AND token = 'xwakWIJVqAL+z6gTcE0ySpt2t2g7RySZNqC/mXoZXKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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