SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e6c924d818922a8bd849ee8ebff236fd30579484ee80834fdd885f11dbd967d' 
  AND token = 'E4aBWkB159tvEoFAhf8IQTsPYNytpjU+Zc65MgmFZ/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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