SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '466ab05b5e900c6e7912242c3cf4691416d59ad8facc5593f1a2f584bd4a18be' 
  AND token = 'UwVZ9sQoiYPzk/7Ud1fhyTiZ1vW9KK1RQLRgCyWaGKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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