SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a1ade08c84673616a89c91627965581ebf38d034dde4c410b4b7dcb7613344dc' 
  AND token = 'cSwmidmauOdSbqRQES4jx6TX54+OUEh4ykIi3M1IUMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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