SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '852a7666e7bbf847ad124c9b74aa5b92e9acb97526c955b6ddb4166817b99537' 
  AND token = 'IvxZ1P8qw/yTVPGHqpYRsyY1J4JKzT+V4ESf0YUinpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}