SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b114c218d3b5d1d1f1178f95c8adc7bf0999cc483b53bc9f4a787cbed10b8b4' 
  AND token = 'RZdgAtLcDCtoFPwKKSyfJFGY4jVQol/BKZJ5+iO+QvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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