SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b8f1a1944348a4bfb67bea4c197dd90f773be3e613f96653243d653734a8164' 
  AND token = 'CQRuYh4mj+gK4f0lO2Ut7MLDvGgqDqiT4lKjKYF09yk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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