SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fc43c9746aa4a581e6ca7502ca8d38ab19cba687134f6369a1336ef63d5b69c' 
  AND token = 'ABAhiOCvPWOoJccFzgCC3Y2fTp5Dm5tnWCsg/jKohXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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