SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9743db7a93592215d652e604764c34a013791a8929ccff82905285adc7a5ce09' 
  AND token = 'daOf8jFvw+5W/ascxOEnNNpGMReah4Nc/vxFjEvsSjo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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