SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2064734c7b8f06908e3a0f2ee739c4ccaa3e068b509bf8c56a5dc714e597590' 
  AND token = 'gwOu5GfGRvZ/DGp/5VCtKhssFjbjP+qPG/I27dM8Siw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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