SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3faf44f18dbc549efa275b918a524a86448fd06c3625d0266895867f87187afe' 
  AND token = 'HgjY8wrRSsJPMqg5JghA8iWn4cG7m1H8rd0vRKxxdLI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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