SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05394bdfff7d13ede9307d46aa1aca7c89269f314870ba2f49726674d2a411cd' 
  AND token = 'woRLGiMZOwZdYyeqpJDzOP4b5BlQXTDbsu2io/9vRII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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