SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72e714972f06951755b8d1f91c778f64cfd9472dccd263510eb7854c4c228628' 
  AND token = 'mc3ILXZ0CDLXaMQD8v6tHbVkPKhhxr76lke7YnC0E/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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