SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '314a69a4b33b9ad11818ce86326118ab976104ad4a96cd14a1a95b0d61a7462f' 
  AND token = 'arbS2DIoRc+ojVwaEHDZkYFAZ5e7D3WrgH62jc3UV0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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