SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0df7c279cda724d2c278c2eca9f5ddd9e2497216e0a231872cbba1cfb04b060' 
  AND token = 'c2Qwvm75miZsa5sgXwXZnQzd4vtZwl8rs4NFVP2zxOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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