SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbc52cc4dc257989b87233ed46ab65438481fde58a1db924c804f31aa5358380' 
  AND token = 'JmozKylMWerWq7sJxuRK/yHKXZzAdqxH67eKQXHUqtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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