SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98cbeac7ed2b499ed2549c6268c23d966604beadd91b0dc9a4f033d32020af70' 
  AND token = 'M74PrGbg4iTBgWlbH/rSyS5yl88QVcUnNDfJWjwp4Ro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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