SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16abc009538aa723caae70620f4af922978b27ce89d830cfa5fc288c3cc7d067' 
  AND token = 'OFytMkscWwPocJgiEuBCuaIjKJkV2W9n7pC4iR6rc/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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