SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10dcbc3a194de3a1ad3a9cadbb527700fcdbc12161b17dea90274a11120e2a9b' 
  AND token = 'B4kwwVXe0dJtFpZ981kDlUwskUYK0WSvRlmtvsuSyRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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