SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b93696885cb30c895a45bf22125a5a2f8c16029695aafebc760d37eea97d1e16' 
  AND token = 'y/XuOmfuLqgcy+67+Qr5/a4GHWravmwWtliXj2p2+WY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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