SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11d1169bfe039be0f3c18acbf01c348a23991484e441e315d017641db61b7795' 
  AND token = '0Eb0ve1pfAfO6XqwcpFGlvv7YBv4yZa9YXmfpy5ds4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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