SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ec4adcc1ea4a91abf8e7c8090c7b084c95a15dee934770264604adeeb7b870e' 
  AND token = 'EuzxtlkP9JCkdzCS2ztnXPZgAiBJsZKUonaZAZ0bmH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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