SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf9e6db5a192888c668780d2b981075603bd2511288b7d106da8348096c36b0e' 
  AND token = 'XFa6snYGi6MLFByF3ZCXkfSxSzYSItX+UvS2jYdXaI0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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