SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f220f63d3276df421fe49c3c840cd2694a35bfd2b0b2a37feb91fd5504216287' 
  AND token = '8WDwuO8lK4SRIFugcSqWYe6Vo/o6u4KDmuZOJ9hqEwQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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