SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd52efcc470eb10b50be19cab9689c32ea30c028ce5110fbf0ed01083eecd4b0' 
  AND token = 'Anz3HVG1TOG3LgHgCyw/kTflhq+iluEHethPyyFwLBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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