SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '883dea4687a04df0c668bbf072aed5f190fe042958b90f3273c4d1fc34e37f16' 
  AND token = 'XNZDnVZVzJV9Fm4Vzyj7yrnm/SvmDowk3KjlJ54E/PM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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