SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4271c5a7da8c64124623e3a924bcd1075eee4e2a2f390ad6406232a9f9175a6b' 
  AND token = 'Px11LTXD4KVAYn6e8tzARYhchmVaEaM2NIV10zR7B0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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