SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45eab97b2bb1afb5b0626560668bed6d723b9c9194276b96afc6ebbbfe51c4a9' 
  AND token = 'RIJRBsQpQJ4LY7lgd8iEIOrhMyHARXdwADCWK4VB8iM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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