SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a869032278d1c8d8cbecdf434b9952d9e046fb80d716fcc1d7b975144951e9e6' 
  AND token = 'yY/50ilERMheqCxV+XfBjKT2bKPZJrfVQdEPKCx/zpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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