SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49cff8548db20d98f94128ad30069d26a7b444374d329d1c0e468f9870691586' 
  AND token = 'QzWVMQjDkyXh1Iagt5jtcPbFHgqqAkPseH4Zt40joEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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