SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e17a7d0424f306f6df7bb6358825c4d46210ff2e87d5c783831153cda4b00fd3' 
  AND token = 'R0rkBsSG6oh1lITtDqEi1ja/dGVKciqxw7Fr4TH9+cA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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