SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92c09d712c833d6ab17a3912a4512a365c67724d47fab91ef35053a264547883' 
  AND token = 'gqGWasHO+vqXcKfOT9+xr89R2M2cjgBqtnDaFej3Jng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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