SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cab5f6da112cc84811b999ecf88fd5d496d5ed7ab4a6240ca111283843094f8' 
  AND token = 'MQHFbdaLmB+RQM3VqgKYsbjDKTiX+BuZav+uuFRgQQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00326

JSON explain

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