SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8318324036d0ebd168ae230fb94104287021ec122dad06f30cb8ae3c0b08ddd' 
  AND token = 'ZyD78ku7chBB/rPvHqwtoysoE51bCTKU6tcMRSPgKU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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