SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63c4f8a1670ce020af92333509468b7287019d00851e0c7bddc61859ccba32b7' 
  AND token = 'jKdQbOmxYOojAOc+TgH3NxZbKiGotULRTHa4xWH3MYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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