SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '812053041956a76bb0811aad106d7369574276c5366e9d581c2903b3f8eb10d0' 
  AND token = 'JAPvOwBGo0cRCbzuz3sX/GIISXgJghvYmqaJDg0nOho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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