SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20dc2c787f902ea17b4bdd05f253c0304a70f7f31a89a7cfca7898d0f5083669' 
  AND token = 'F6rinF4BRmVYSk60iaahzL4F0ae9WMAMS/2dMJ5nsR0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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