SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95ccb289ad01681c94aeff469ba646fce1f7dbd35a16040ff92500820b5b3c89' 
  AND token = '2UAbevPJz97GHTESN+lHsTjo4iiIT/mEHIjCmyB7TLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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