SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '651350c40b3708735bd9f4d246ec0ffddf304b69f9b39d49baf1580b18715247' 
  AND token = 'S+7OZVRVVqA88fWRaZmEhjbQHAMHf8QZp+G/PtjH3qI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}