SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45a1332b145d660956847037427882205e6c5d99aa45f11e479ba6cba4878455' 
  AND token = 'Q6jW9/KtCB+0VB+QwfKFLQopFFBVLBp+pRdoy1tsqcM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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