SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72419d5afda45137635092906ddbfcd0f5d75fc4e5a8d064a56a3ace114640de' 
  AND token = 'sajAVNa+nntl/BGJFuI0hWacL1ElSXMKsiKkhsV4NLU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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