SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbef27037dafb2deca5434e774fd0fd33dea9626ca3a4d7de7edf99cebd29c5d' 
  AND token = 'q9bRboiFzFBDSWe+FCy08TnzX0ZYFkC4ViwDlO1U/18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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