SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '264123ba7947183f81fb5a161c0c9329c08a6f36d70caf152c3b7075ab333e64' 
  AND token = 'rkRxkh5LSQyZlpEDeNKdTDQNbImeek/HncPa/4F3di4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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