SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '492323e1f28c559169863f06427da8bbd08e4ff9bb8ef591c7bfdc1d381dda69' 
  AND token = 'yXvs3wYkhidHPMvKBfAn94WvKvlzKFfbLaSyQ8DR4rc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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