SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b923c5db3d094c707d0c3cf25b40a50eb0219c7042ea2e8ad5aaf519cf7b5fef' 
  AND token = 'bcGiNpw4YrkClvKSdVuzT3X3fHNpfH1jWHeb7IVo7Kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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