SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c6cc0946ceebaac2b671011b5f841bfc8b3fbe48c70c59fb7cb9458123cdafb' 
  AND token = 'gAe/KxuCcXqVUT+lc2RsoMs51ddx+47jyVrOXyS8hZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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