SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98f8230940f0a1be59d1e86b578e686ecd8ed3bbd81c745b390002b5c6cce9f6' 
  AND token = 'Yju5ALBDt2pUoSKCwqlJwOPWSYxLTXG6vtx8H1Tx+0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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