SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce9dcd67614796da83c1afa3216f74605321073368acf4bd8d1d4da5b4b625d6' 
  AND token = 'rdEAt1XlK7jlWfG/pqvPayu9+F6N1tJqDb9sOZKDY8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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