SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14d9b7596b1cf6244852c9bfb93c22a4a3b7045d34a4ee1573db5a8acbee66b8' 
  AND token = '/O948nVtjvvJRQJ6EUvyVnY6XuHQPwqBEsVGDNRE5Ss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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