SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3de4555cdc2f16d844c2fb1bf6081445face826a0177e1789f33e612f6a7328c' 
  AND token = 'jFNiSiZ0yPEdLOTd5w/yu8NbNq5RE8H7S2fKYxJVp1c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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