SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b295ff9ccb12536143ff42c46a035c4d10fba3cc9a1637afdf4e8836b932b684' 
  AND token = 'xVDiS5bDSgvlfQ/kb7ZcouZnjFzd/C8Nnvy0LPPYfww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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