SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff94db127111ce2d37e64ebc0d937a19d8c096aab72f35234c444e5e6ce138b6' 
  AND token = 'iICwGn/nmRXFvEWbxEdQ7pDOQB7xfHKezUIv5soRs9U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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