SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82634a1b50d15794498c878a090534f07209a6b11e0da1414681919a4095605e' 
  AND token = 'tMzwSJCqYF1XAmUyd4kihzQcBUkQ+DCZSVvZ6JqYOII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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